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From: Yann Droneaud <ydroneaud@opteya.com>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	Yann Droneaud <ydroneaud@opteya.com>
Subject: [PATCH 3/3] fs: documents seq_open()'s usage of file->private_data
Date: Tue,  5 May 2015 00:19:15 +0200	[thread overview]
Message-ID: <e5908204510326710a9628469bbcfa1595823f64.1430777196.git.ydroneaud@opteya.com> (raw)
In-Reply-To: <cover.1430777196.git.ydroneaud@opteya.com>
In-Reply-To: <cover.1430777196.git.ydroneaud@opteya.com>

seq_open() stores its struct seq_file in file->private_data,
thus, it must not be modified by user of seq_file.

Link: http://lkml.kernel.org/r/cover.1430777196.git.ydroneaud@opteya.com
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
---
 fs/seq_file.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/seq_file.c b/fs/seq_file.c
index cb9c3dbd1a1e..69d13f62d885 100644
--- a/fs/seq_file.c
+++ b/fs/seq_file.c
@@ -48,6 +48,8 @@ static void *seq_buf_alloc(unsigned long size)
  *	ERR_PTR(error).  In the end of sequence they return %NULL. ->show()
  *	returns 0 in case of success and negative number in case of error.
  *	Returning SEQ_SKIP means "discard this element and move on".
+ *	Note: seq_open() will allocate a struct seq_file and store its
+ *	pointer in @file->private_data. This pointer should not be modified.
  */
 int seq_open(struct file *file, const struct seq_operations *op)
 {
-- 
2.1.0


      parent reply	other threads:[~2015-05-04 22:19 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-05-04 22:19 [PATCH 0/3] seq_file allocation in seq_open() Yann Droneaud
2015-05-04 22:19 ` [PATCH 1/3] fs: use seq_open_private() for proc_mounts Yann Droneaud
2015-05-04 22:19 ` [PATCH 2/3] fs: allocate structure unconditionally in seq_open() Yann Droneaud
2015-05-04 22:19 ` Yann Droneaud [this message]

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